Cardiac magnetic resonance imaging study for quantification of infarct size comparing directly serial versus single time-point measurements of cardiac troponin T.

OBJECTIVES: We compared single-point cardiac troponin T (cTnT) measurements with parameters from serial sampling during 96 h after acute myocardial infarction with magnetic resonance imaging measured infarct mass. BACKGROUND: Contrast-enhanced magnetic resonance imaging (CE-MRI) allows exact quantification of myocardial infarct size. Clinically, measurement of cardiac biomarkers is a more convenient alternative. METHODS: The CE-MRI infarct mass was determined 4 days after primary percutaneous coronary intervention in 31 ST-segment elevation myocardial infarction (STEMI) and 30 non-ST-segment elevation myocardial infarction (NSTEMI) patients. All single-point, peak, and integrated area under the curve (AUC) cTnT values were plotted against CE-MRI infarct mass. RESULTS: All single-point and serial cTnT values were significantly higher in STEMI than in NSTEMI (p < 0.01) patients. Except for the admission values, all single-point values on any of the first 4 days, peak cTnT and AUC cTnT were found to correlate comparably well with infarct mass. Among single-point measurements, cTnT on day 4 (cTnTD4) showed highest correlation and performed as well as peak cTnT or AUC cTnT (r = 0.66 vs. r = 0.65 vs. r = 0.69). Receiver-operator characteristic analysis demonstrated that cTnTD4 >0.84 microg/l predicted infarct mass above median as well as peak cTnT >1.57 microg/l or AUC cTnT (receiver-operator characteristic for AUC: 0.839 vs. 0.866 vs. 0.893). However, estimation of infarct mass with cTnTD4, peak cTnT, and AUC cTnT was worse in patients with NSTEMI (r = 0.36, r = 0.5, r = 0.36) than in STEMI (r = 0.75 vs. r = 0.65 vs. r = 0.76). CONCLUSIONS: All single-point cTnTs, except on admission, give a good estimation of infarct size and perform as well as peak cTnT or AUC cTnT. Infarct estimation by single-point measurements, particularly cTnTD4, may gain clinical acceptance because the measurement is easy and inexpensive.     

Serum amyloid A predicts early mortality in acute coronary syndromes: A TIMI 11A substudy

OBJECTIVES: We evaluated the ability of serum amyloid A (SAA), alone and in combination with a rapid qualitative assay for cardiac-specific troponin T (cTnT), to predict 14-day mortality in patients with unstable angina or non-Q wave myocardial infarction (NQMI). BACKGROUND: Elevated C-reactive protein (CRP) has been associated with adverse outcomes in unstable coronary syndromes but data regarding its acute phase counterpart, SAA, are conflicting. METHODS: Serum amyloid A measurement and a rapid cTnT assay were performed on blood obtained at enrollment into Thrombolysis in Myocardial Infarction 11A, a dose-ranging trial of enoxaparin for unstable angina and NQMI. RESULTS: Serum amyloid A was higher in patients who died compared with survivors (6.28 vs. 0.75 mg/dL, p = 0.002). Among patients with a negative rapid cTnT, mortality was higher for those in the top quintile of SAA (6.1 vs. 0.7%, p = 0.003). Patients with both an early positive rapid cTnT (< or =10 min until assay positive) and SAA in the fifth quintile had the highest mortality followed by those with either markedly elevated SAA or an early positive rapid cTnT, while patients with both a negative rapid cTnT and SAA in quintiles 1-4 were at very low risk, (9.1 vs. 3.6 vs. 0.7%, p <0.002). CONCLUSIONS: Similar to CRP, baseline elevation of SAA identifies patients hospitalized with unstable angina and NQMI at higher risk for early mortality, even among those with a negative rapid assay for cTnT. These data support further investigation of inflammatory markers used alone and in combination with cardiac troponins for risk assessment in unstable coronary syndromes.     

高敏肌钙蛋白T与常规肌钙蛋白T在急性冠状动脉综合征中的对比研究

目的对比分析急性冠状动脉综合征(ACS)患者血清高敏肌钙蛋白T(hs-cTnT)与常规肌钙蛋白T(cTnT)早期诊断急性心肌梗死(AMI)的价值。方法连续入选拟诊ACS患者215例,依据诊断分为AMI组59例,不稳定性心绞痛(UAP)组103例,非冠状动脉粥样硬化(非CHD)组53例。入院即刻测定血清cTnT、hs-cTnT水平。应用ROC曲线比较hs-cTnT、常规cTnT对AMI早期诊断的敏感性和特异性。结果 AMI组血清hs-cTnT和常规cTnT均高于UAP组和非CHD组(P<0.05)。hs-cTnT与常规cTnT诊断AMI的ROC曲线下面积分别为0.936、0.880(P=0.000);hs-cTnT敏感性为88.1%,特异性为84.6%,cTnT分别为76.3%、99.4%。hs-cTnT水平与Gensini积分呈正相关(P<0.05),与冠状动脉病变支数无关(P>0.05)。结论 ACS患者中,hs-cTnT对早期诊断AMI可能较常规cTnT更敏感,可尽早检测出更多的AMI患者。     

Impact of coronary artery remodeling on clinical presentation of coronary artery disease: an intravascular ultrasound study

OBJECTIVES: We examined the association between the features of the culprit lesion in coronary artery disease (CAD) and clinical presentation as shown by intravascular ultrasound (IVUS). BACKGROUND: The association between coronary remodeling pattern and clinical presentation of CAD is unclear. METHODS: We analyzed 125 selected patients who underwent preintervention IVUS. Acute myocardial infarction (AMI) and unstable angina pectoris (UAP) were categorized as an acute coronary syndrome (ACS), and stable angina pectoris (SAP) and old myocardial infarction (OMI) as stable CAD. Coronary remodeling patterns and plaque morphology of the culprit lesion obtained by IVUS were analyzed in terms of their association with clinical presentation or angiographic morphology. RESULTS: Angiographically complex lesions were associated with ACS and OMI. In patients with a complex lesion, positive remodeling was observed more frequently than in those with a simple lesion. In AMI and UAP, positive remodeling was observed more frequently than in SAP and OMI (82% vs. 78% vs. 33% vs. 40%, respectively, p < 0.0001). The remodeling ratio was greater in AMI and UAP than in SAP and OMI (1.26 +/- 0.15 vs. 1.11 +/- 0.10 vs. 0.94 +/- 0.11 vs. 0.96 +/- 0.13, respectively, p < 0.0001). Furthermore, within ACS, the remodeling ratio was greater in AMI than in UAP (1.26 +/- 0.15 vs. 1.11 +/- 0.10, respectively, p < 0.05), whereas the frequency of positive remodeling was not different. CONCLUSIONS: Positive remodeling was more frequently observed in ACS than in stable CAD. Moreover, the degree of positive remodeling was greater in AMI than in UAP. These results may reflect the impact of remodeling types and its degree in the culprit lesion of CAD on clinical presentation.     

Clinical association between renal insufficiency and positive troponin I in patients with acute coronary syndrome

BACKGROUND: Whether renal insufficiency (RI) influences troponin levels in patients with acute coronary syndromes (ACS) is controversial. We attempted to determine whether there is an association between RI and troponin I (TnI) elevation in patients presenting with ACS. METHODS: We studied 764 consecutive patients with ACS admitted to our institution from January 1999 to June 2000. Patients were identified prospectively and data were collected through chart review of all cases with an admission diagnosis of ACS. In order to assess the relationship of TnI and RI, we calculated the creatinine clearance (Cr-Cl) for all patients. We conducted an analysis of variance comparing TnI in quintiles of patients with lowest to highest Cr-Cl. RESULTS: Among 764 patients, 173 patients had a discharge diagnosis of ST elevation myocardial infarction and 591 had non-ST elevation myocardial infarction. There was no correlation between peak TnI levels and renal function as measured by Cr-Cl in the entire cohort with ACS and in the subgroups with ST elevation myocardial infarction and non ST elevation myocardial infarction. CONCLUSIONS: This large cohort study demonstrates that there appears to be no association between RI and positive TnI in patients with ACS.     

Classification and risk stratification of patients with acute chest pain using a low discriminatory level of cardiac troponin T

BACKGROUND: Cardiac troponins are the biochemical markers of choice for the evaluation of acute coronary syndromes (ACS). Using the first-generation test, most studies related adverse outcome to > 0.20 or 0.10 microg/l cardiac troponin T (cTnT) levels. With the highly sensitive and specific second- and third-generation assays, cTnT is undetectable in most healthy individuals. HYPOTHESIS: We evaluated whether a lower cTnT level, within 24 h of admission, could indicate an increased risk of future complications. METHODS: During 1998-1999, clinical data were collected in 260 patients with ACS. Cardiac troponin T was measured at arrival, and 4, 8, and 12-24 h thereafter. The maximum cTnT value was then used to assess, over a 15-month follow-up period, the cumulative risk of death or myocardial infarction (MI), as well as rates of events according to quartiles of cTnT values. RESULTS: Patients with < or = 0.03 microg/l cTnT levels had the lowest rate of adverse events and the best Kaplan-Meier event-free survival curve. Increasing cTnT levels were associated with stepwise increases in mortality rates and with a constant 10-fold increase in MI rates during follow-up. CONCLUSIONS: A low threshold cTnT elevation is recommended to assess the risk of ACS. All cTnT elevations > 0.03 microg/l predict a higher risk of MI during follow-up, whereas increasing values predict mortality in relation to the amount of elevation.     

Ischemia Modified Albumin for the assessment of patients presenting to the emergency department with acute chest pain but normal or non-diagnostic 12-lead electrocardiograms and negative cardiac troponin T

BACKGROUND: The diagnosis of myocardial ischemia in patients with acute chest pain at rest but non-diagnostic electrocardiograms (ECG) is problematic. Ischemia Modified Albumin (IMA) is a new biochemical marker of ischemia, which may be useful to characterise acute coronary syndrome (ACS) patients. METHODS: We studied 131 patients (mean age 58.5 years; 95 male) presenting to the emergency department with symptoms suggestive of ACS but with normal or non-diagnostic ECGs. Cardiac troponin T (cTnT) and IMA were measured within 3 h of last chest pain episode. Based on hospital diagnostic test results, patients were classified as having ACS or non-ischemic chest pain (NICP), by two independent cardiologists unaware of IMA results. RESULTS: Mean IMA levels (U/ml) were higher in patients with ACS (98.3+/-11) compared to patients with NICP (85.5+/-15); p<0.0001. IMA levels >93.5 U/ml demonstrated a sensitivity and specificity of 75% for the diagnosis of ACS; area under the receiver operator characteristic curve 0.78 (95% CI: 0.70-0.85). If we applied the manufacturer cutoff point of 85 U/ml, the sensitivity of IMA increased to 90.6% with a specificity of 49.3% (negative predictive value=84.6%). In combination with cTnT (6-12 h) (>0.05 ng/ml), the sensitivity increased to 92.2%. After multivariate analysis, IMA levels >85 U/ml (odds ratio=14.6 [95% CI 4.4-48.4]; p<0.0001), age and prior myocardial infarction were independent predictors of ACS. CONCLUSION: IMA may be a useful biomarker for the identification of ACS in patients presenting with typical acute chest pain but normal or non-diagnostic ECGs.     

Correlation between ST-T-segment changes with markers of hemostasis in patients with acute coronary syndromes

BACKGROUND: Disturbance of the hemostatic and the inflammatory system plays an important role in the pathophysiology of acute coronary syndromes (ACS). Their markers have been shown to predict further coronary events in patients with ACS. The prognostic value of the admission electrocardiogram (ECG), which is commonly used to evaluate ischemia, was studied previously. We investigated the correlation between serum markers of the hemostatic/inflammatory system and ECG changes in ACS. METHODS: A standard 12-lead ECG was obtained from 85 patients with ACS on admission (0d). Markers of the hemostatic and inflammatory system were measured on admission and after 2 days (2d). RESULTS: Patients with ST-T-changes had higher fibrinogen and thrombin-antithrombin III complex (TAT) levels than patients without ECG alterations at both times (fibrinogen: 0d: 492 +/- 38 vs. 357 +/- 36 mg/dl, p < 0.01; 2d: 633 +/- 55 vs. 440 +/- 50 mg/dl, p < 0.02; TAT: 0d: 7.2 +/- 1.3 vs. 3.6 +/- 0.7 microg/l, p < 0.05; 2d: 5.3 +/- 0.9 vs. 3.2 +/- 0.5 microg/l, p < 0.05). Tissue-type plasminogen activator (TPA) was elevated in patients with ECG changes initially (10.1 +/- 0.6 vs. 7.2 +/- 0.7 ng/ml, p < 0.02). D-dimers, the acute-phase proteins C-reactive protein, serum amyloid A and the soluble adhesion molecules showed no significance. CONCLUSIONS: The data reveal a correlation between electrocardiographic changes and hemostasis in patients with ACS. The association of myocardial damage and a disturbed hemostatic system might stratify patients who are at high risk of suffering further coronary events.     

Patients with non-ST-elevation myocardial infarction and without chest pain are treated less aggressively and experience higher in-hospital mortality

BACKGROUND: Lack of chest pain or atypical pain does not exclude acute coronary syndrome (ACS). AIM: To assess demographic and clinical characteristic as well as treatment strategies in patients with atypical chest pain on admission in hospitals without on-site invasive facility (IF). METHODS: Twenty-nine community hospitals participated in the Registry of Acute Coronary Syndromes. A total of 2382 patients with ACS were enrolled. Patients admitted to hospitals with suspected ACS were stratified according to their pain symptoms as either typical (TS) or atypical which also included lack of pain (ATS). RESULTS: Of all patients with initial ACS diagnosis 152 (6.4%) presented without chest pain on admission. Patients from group ATS in comparison to group TS were more often women (49 vs. 39%; p=0.01), and less frequently had past medical history of coronary artery disease (54.3 vs. 72.5%; p <0.0001), myocardial infarction (15.2 vs. 32.1%; p <0.0001), arterial hypertension (65.6 vs. 74.5; p <0.0001) or renal insufficiency (1.3 vs. 5%; p=0.04). Invasive treatment was undertaken in 9.2% of patients from group ATS and in 14.6% from group TS (p=0.049). In-hospital mortality among all patients remaining in community hospitals for conservative treatment was similar in both groups (ATS vs. TS: 8.7 vs. 5.9%; p=NS). Among patients with typical and atypical symptoms the occurrence of ST-segment elevation myocardial infarction (STEMI), non-ST-segment elevation myocardial infarction (NSTEMI) and unstable angina (UA) was similar. Patients with NSTEMI and UA with atypical symptoms were less likely transferred for invasive diagnostic, for NSTEMI 9.4 vs. 18.1% (p=0.03) and for UA 6.1 vs. 12.9% (p=0.04). In-hospital mortality was similar among typical and atypical groups in STEMI and UA patients. However, it was significantly higher among NSTEMI patients with atypical chest pain treated conservatively (3.6 vs. 0%; p=0.05). CONCLUSIONS: There is a significant group of ACS patients without chest pain on admission who are usually women with less severe past medical history. This subset of patients is treated less aggressively in terms of antiplatelet therapy and invasive approach. It is patients with diagnosis of NSTEMI who due to being misdiagnosed due to their atypical chest pain have poorer outcome.     

Prognostic value of free plasma homocysteine levels in patients hospitalized with acute coronary syndrome

Elevated total plasma homocysteine is an established risk factor for cardiovascular disease. Experimental evidence suggests that non-protein-bound free homocysteine is particularly hazardous to the vascular endothelium. This study evaluates the predictive role of free plasma homocysteine levels on cardiovascular endpoints in patients with acute coronary syndrome (ACS). In a cohort of 379 hospitalized patients with a diagnosis of myocardial infarction or unstable angina pectoris, total and free plasma homocysteine levels were measured by high performance liquid chromatography. The patients were followed for a median 2.7 years. The primary endpoint was a composite of cardiovascular death, myocardial infarction and stroke during follow-up. Stepwise Cox regression was used for multivariate analysis. Primary outcome events occurred in 82 patients (22%) with a median time to event of 6 months. The unadjusted hazard ratio for a free homocysteine level >4.11 micromol/L was 2.16 (95% confidence intervals [CI] 1.36 to 3.42) compared with the 4 lower quintiles. After adjusting for the covariates the hazard ratio was 2.25 (95% CI 1.41 to 3.58, p = 0.01). Compared with the lower 4 quintiles, patients with a total homocysteine level >22.4 micromol/L had a 2.09-fold higher risk (95% CI 1.31 to 3.35) for an event during follow-up. Adjusted for age, discharge diagnosis, serum creatinine, history of atherothrombotic events, and diabetes mellitus, the adjusted hazard ratio was 1.37 (95% CI 0.83 to 2.25, p = 0.22). In conclusion, plasma free homocysteine levels >4.11 micromol/L are a significant and independent risk factor for recurrent cardiovascular events in patients hospitalized for ACS, although total plasma homocysteine levels have no predictive value.     

Procalcitonin in patients with acute coronary syndrome: correlation with high-sensitive C-reactive protein, prognosis and severity of coronary artery disease

OBJECTIVES: The aim of this study is to determine the relation of high-sensitive serum C-reactive protein (hsCRP) and procalcitonin with presence and severity of coronary artery disease and early prognosis in patients with acute coronary syndrome (ACS). METHODS AND RESULTS: Procalcitonin and hsCRP levels were measured at admission and after 48 hours in 50 patients (41 men, 9 women) with ACS. The patients were assigned to three groups according to their clinical diagnosis: unstable angina pectoris (UAP) (Braunwald III-B), non-ST-segment elevation myocardial infarction (NSTEMI) and ST-segment elevation myocardial infarction (STEMI). Incidences of adverse cardiac events were recorded in a 3-month follow-up. Coronary angiography was performed to evaluate presence and severity of coronary artery disease. In the groups of STEMI, NSTEMI and UAP, procalcitonin (P = 0.01 3, P = 0.045 and P = 0.000 1, respectively) and hsCRP (P = 0.000 1, P = 0.01 and P = 0.00 1, respectively) levels were significantly increased. No significant correlation was found between these markers and the presence and severity of coronary artery disease.There was no correlation between procalcitonin and hsCRP levels at admission and after 48 hours and primary end points after 3 months except in the group of UAP with revascularization procedure. In the group of UAP, hsCRP levels at 48 hours were found higher in the patients with a revascularization procedure (P = 0.04). CONCLUSIONS: In conclusion, levels of hsCRP and procalcitonin are increased in patients with ACS but failed to correlate with severity of coronary disease and early prognosis.     

急性冠脉综合征测定血浆同型半胱氨酸和脑钠肽的意义

目的：探讨急性冠脉综合征（ACS）患者血浆脑钠肽（BNP）和同型半胱氨酸（Hcy）的变化及其临床意义。方法：测定以34例冠脉造影正常，心功能正常者作为对照。采用荧光免疫抗原抗体结合方法测定30例稳定型心绞痛（SAP）患者人院后第二天清晨及82例ACS患者症状发作后24h内的血浆BNP水平。采用高效液相色谱法测定所有患者人院第二日清晨血浆Hey水平。结果：ACS患者血浆BNP浓度分别高于SAP组及对照组（P〈0．01）。心肌梗塞（AMI）组BNP浓度高于不稳定型心绞痛（UAP）组（P〈0．05）。ACS组的Hey水平分别高于SAP组及对照组（P均〈20．01）。结论：ACS患者血浆BNP和Hey水平明显升高，AMI的较UAP的更高，提示两者在ACS的发病机制中起重要作用。     

Electrocardiography and prediction of myocardial damage in patients with acute pulmonary embolism

Acute pulmonary embolism (APE) may lead to myocardial necrosis detected by elevation of cardiac troponin levels. We tried to assess, if electrocardiographic abnormalities may help to define APE patients with myocardial damage and at high risk of complicated clinical course. Therefore we analyzed 50 patients (34F) aged 64.6 +/- 16.9 with confirmed APE. On admission 12-lead standard ECG was recorded and cardiac troponin T (cTnT) was determined quantitatively (Roche). Serum cTnT levels > 0.01 ng/ml, regarded to indicate myocardial injury, were detected in 29 (58%) patients. ST segment depression in ECG was found in 24% of all patients and was more frequent in cTnT + then in group without myocardial injury (41.4% vs 0%, p=0.004). Complicated clinical course and death in acute pulmonary embolism were also more frequently observed in group with ST segment depression (47.1% vs 12.1%, p = 0.03 and 75.0% vs 14.3%, p = 0.02 respectively). Although negative T waves were slightly more frequent in patients with elevated serum troponin T level (65.5% vs 42.9%) and in patients, who died of pulmonary embolism (62.5% vs 54.8%), the difference did not reach statistical significance. Conclusion: ST segment depression detected in standard ECG in patients with APE suggests myocardial injury and may indicate unfavourable clinical course.     

Clinical significance of cardiac troponins I and T in acute heart failure

BACKGROUND: Elevated cardiac troponin (cTn) levels are relatively common in acute heart failure (AHF). AIMS: To evaluate the prevalence and prognostic significance of elevated cTnI and cTnT in AHF. METHODS: FINN-AKVA is a prospective, multicenter study in AHF. In this analysis, 364 non-ACS patients with measurements of cTnI and cTnT taken on admission and 48 h thereafter were analyzed. RESULTS: Of the 364 AHF patients, 51.1% had cTnI and 29.7% cTnT levels above the cut-off value. Six-month all-cause mortality was 18.7%. Both cTnI (OR 2.0, 95% CI 1.2-3.5, p=0.01) and cTnT (OR 2.6, 95% CI 1.5-4.4, p=0.0006) were associated with adverse outcome. The mortality risk was proportional to the magnitude of cTn release. On multivariable analysis, Cystatin C (OR 6.3, 95% CI 3.2-13, p<0.0001), logNT-proBNP (OR 1.4, 95% CI 1.0-1.8, p=0.03) and systolic blood pressure on admission (/10 mm Hg increase, OR 0.9, 95% CI 0.8-0.9, p=0.0004) were independent risk markers, whereas the troponins were not significantly associated with increased mortality. CONCLUSIONS: cTn elevations are frequent in AHF patients without ACS. cTnI is more often elevated than cTnT. Both cTnI and cTnT elevations are associated with increased mortality proportional to the degree elevation but they do not act as independent risk markers.     

Interaction between smoking and the glycoprotein IIIa P1(A2) polymorphism in non-ST-elevation acute coronary syndromes.

OBJECTIVES: The goal of this study was to determine the interaction between smoking and the glycoprotein IIIa P1(A2) polymorphism in patients admitted with non-ST-elevation acute coronary syndromes (ACS). BACKGROUND: An increased incidence of the P1(A2) polymorphism in smokers presenting with ST-elevation acute myocardial infarction (AMI) has recently been reported. We, therefore, postulated that, as a consequence of this interaction, fewer smokers with the P1(A2) polymorphism would present with non-ST-elevation ACS. METHODS: We performed a prospective cohort analysis of 220 white Caucasoid patients admitted with non-ST-elevation ACS fulfilling Braunwald class IIIb criteria for unstable angina who were stratified by smoking status. RESULTS: There were twice as many nonsmokers as smokers. Nonsmokers compared with smokers were older (mean [SD]; 63.9 [11.2] vs. 57.6 [10.3]; p < 0.0001), more likely to have had a previous admission with unstable angina (24.3% vs. 13.2%; p = 0.051) and AMI (45.8% vs. 30.3%; p < 0.026), more likely to have undergone revascularization (24.3% vs. 1.8%; p = 0.028) and were more likely to be on aspirin on admission (60.4% vs. 44.7%; p = 0.026). The proportion of nonsmokers positive for the P1(A2) polymorphism was equivalent to that expected for this population but was significantly reduced in smokers (28.7% vs. 10%; Pearson chi-square = 9.09, p = 0.0026). In a logistic regression model, the odds ratio (OR) for being positive for the P1(A2) polymorphism was significantly reduced by smoking (OR [interquartile range]: 0.26 [0.11 to 0.62]; p = 0.0026). CONCLUSIONS: There is a significant reduction in the P1(A2) polymorphism in smokers admitted with non-ST-elevation ACS compared with nonsmokers, which suggests an interaction between smoking and this polymorphism.     

Comparison of patients with acute coronary syndrome with and without systemic hypertension

The role of systemic hypertension in acute coronary syndrome (ACS) has not been well studied. We studied consecutive subjects admitted to the University of Michigan Health System (Ann Arbor, Michigan) with symptoms of ACS. Data were collected using a standardized form. This observational study is currently ongoing; we collected data from May 1999 to December 2000 for 979 subjects, 890 of whom also had 6-month follow-up data. Hypertensives represented 64.4% (n = 630) of the total population. In general, hypertensive patients were older than normotensives (66.3 vs 59.9 years, p <0.0001), more often women (38.7% vs 26.9%, p = 0.0002), and had more comorbidities, such as previous myocardial infarction (47.9% vs 33.8%, p <0.0001), congestive heart failure (25.7% vs 12.0%, p <0.0001), and diabetes (36.9% vs 17.8%, p <0.0001). At admission, hypertensives had higher systolic blood pressure. Hypertensives had fewer electrocardiographic abnormalities indicating ischemic changes (67.9% vs 76.3%, p = 0.01) and had fewer incident of acute myocardial infarction (AMI) (70.7% vs 76.1%, p = 0.07) than normotensives. There was consistency over different levels of admission systolic blood pressure. Hypertensives received more oral cardiovascular drugs, and had undergone more invasive procedures. The lower rate of AMI in hypertensives seemed to be related to the higher frequency of a history of percutaneous coronary intervention and coronary artery bypass grafting. However, at 6-month follow-up, age- and gender-adjusted odds ratios for adverse events were equivalent in hypertensives and normotensives, suggesting no continuing differential treatment benefit for hypertensives in the months after the initial ACS episode.     

高敏C反应蛋白与急性冠脉综合征的相关性

目的：探讨高敏C反应蛋白（hsCRP）与急性冠脉综合征（ACS）病变严重程度及预后之间的关系。方法：选择95例ACS患者,其中急性心肌梗塞（AMI）50例、不稳定型心绞痛（UAP）45例,并根据冠脉病变程度分单支血管病变（SVL）组48例和多支血管病变（MVL）组47例。另选40例非ACS患者作为非ACS对照组,测定各组hsCRP、纤维蛋白原、血脂等指标,进行比较。结果：与非ACS对照组比较,UAP组、AMI组hsCRP水平明显升高[（0.85±0.49）mg/L比（10.01±1.73）mg/L比（52.73±2.39）mg/L,P〈0.01],AMI组明显高于UAP组（P〈0.01）;MVL组hsCRP水平明显高于SVL组[（69.11±1.98）mg/L比（10.12±2.01）mg/L,P〈0.05]。Spearman相关分析显示,hsCRP与冠脉狭窄呈正相关（r=0.210,P=0.042）,与纤维蛋白原（r=0.516,P〈0.0001）、血脂水平呈明显正相关（r=0.100～0.159,P〈0.001～〈0.0001）。结论：高敏C反应蛋白与冠脉病变严重程度呈正相关,是冠心病的独立危险因素;测定高敏C反应蛋白水平对急性冠脉综合征的危险分层和预测病变严重程度具有较高的临床参考价值。     

Admission risk assessment by cardiac troponin T in unstable coronary artery disease: additional prognostic information from continuous ST segment monitoring. TRIM study group. Thrombin Inhibition in Myocardial Ischemia.

OBJECTIVES: We investigated whether the addition of 24 h of continuous vectorcardiography ST segment monitoring (cVST) for an early (within 24 h of the latest episode of angina) determination of cardiac troponin T (cTnT) could provide additional prognostic information in patients with unstable coronary artery disease (UCAD), i.e., unstable angina and non-Q wave myocardial infarction. BACKGROUND: Determination of cTnT at admission and cVST are individually reported to be valuable techniques for the risk assessment of patients with UCAD. METHODS: Two hundred and thirty-two patients suspected of UCAD were studied. Patients were followed for 30 days, and the occurrence of cardiac death or acute myocardial infarction (AMI) were registered. RESULTS: One ST segment episode or more (relative risk [RR] 7.43, p = 0.012), a cTnT level > or = 0.20 microg/liter (RR 3.85, p = 0.036) or prestudy medication with calcium antagonists (RR 3.31, p = 0.041) were found to carry independent prognostic information after multivariate analysis of potential risk variables. By combining a cTnT determination and subsequent cVST for 24 h, subgroups of patients at high (25.8%) (n = 31), intermediate (3.1%) (n = 65) and low risk (1.7%) (n = 117) of death or AMI could be identified. CONCLUSIONS: Twenty-four hours of cVST provides additional prognostic information to that of an early cTnT determination in patients suspected of having UCAD. The combination of biochemical and electrocardiographic methods provides powerful and accurate risk stratification in UCAD.     

急性冠脉综合征患者血清同型半胱氨酸和hs-CRP的相关性

目的:探讨急性冠脉综合征(ACS)患者血清同型半胱氨酸水平的变化,评价其与高敏C反应蛋白(hs-CRP)的关系。方法:用免疫比浊透视法测定60例ACS患者和30例对照组血清中hs-CRP水平,以循环酶法测定血清同型半胱氨酸(Hcy)水平。结果:ACS组Hcy水平[(16.75±6.40)mg/L]明显高于对照组[(13.70±6.60)mg/L],P<0.05,AMI组的hs-CRP和Hcy水平明显高于UAP组(P<0.05),且ACS组血清Hcy水平升高[(16.75±6.40)mg/L]时,患者血清hs-CRP水平[(4.475±16.09)mg/L]也相应升高,两者之间呈正相关(r=0.444,P<0.01)。结论:血清同型半胱氨酸水平升高与心肌损伤程度有关,且可能通过hs-CRP加重心肌损伤。     

Management and outcomes of lower risk patients presenting with acute coronary syndromes in a multinational observational registry

OBJECTIVE: To document patterns of risk stratification, management practices, and outcomes among patients with acute coronary syndromes (ACS) presenting without high risk features. PATIENTS: The study was based on 11,885 consecutive patients presenting with non-ST segment elevation ACS enrolled in GRACE (global registry of acute coronary events). Patients without dynamic ST segment changes, positive troponin (or other cardiac markers), or haemodynamic or arrhythmic instability were defined as being at lower risk. MAIN OUTCOME MEASURES: Management and outcomes were compared with high risk presentations. RESULTS: Of 11,885 patients presenting with unstable angina or non-ST segment elevation myocardial infarction, 4252 (36%) were regarded as being at lower risk. Functional testing for risk stratification was performed in 1163 of 4207 (28%) lower risk and 1531 of 7521 (20%) high risk patients (p < 0.0001). Coronary angiography was performed in 1930 of 4190 (46%) and 3860 of 7544 (51%), and echocardiography in 1692 of 4190 (40%) and 4348 of 7533 (58%) of lower risk and high risk patients, respectively (p < 0.0001 for both). Over one third of patients did not undergo further risk assessment with angiography or functional testing (2746 of 7437 (37%) high risk, 1499 of 4148 (36%) lower risk, not significant). Death occurring in hospital was more likely in the high risk cohort (41 of 4227 (1.0%) lower risk v 215 of 7586 (2.8%) high risk, p < 0.0001), whereas rates of recurrent angina during admission and readmission were similar in both groups (1354 of 4231 (32%) high risk, 2313 of 7587 (31%) lower risk, not significant). In the six months after discharge, death or myocardial infarction occurred in 79 of 3223 (2.5%) lower risk patients and 302 of 5451 (5.5%) high risk patients (p < 0.0001). CONCLUSIONS: Globally, further risk stratification after ACS presentation is suboptimal, regardless of presenting characteristics. Although in-hospital death and myocardial infarction are uncommon, recurrent ischaemia is encountered often in both groups. It remains to be seen whether better outcomes may be achieved with wider application of risk stratification and appropriately directed management strategies.